[Preparation of oral sustained-action preparations with a base of biologically degradable polymers. 2. Preparation of matrix tablets with a base of polylactic acid].

It is reported on the preparation and investigation of matrix tablets on the basis of the polylactic acid. Caffeine and phenazone served as model drugs. The release values obtained were analyzed by the equations of Noyes-Whitney and of Higuchi. It was demonstrated, that the solubility and the grain size of the drugs, their content in the tablets and an addition of Heweten 12 have an influence of the release of the drugs. In in vitro-investigations can be shown a hydrolytic degradation of the polymer, but not an enzymatic degradation.